The present embodiments relate to a circuit arrangement of driving electronics of a transmission coil arrangement.
Modem magnetic resonance systems (MR systems or else MRI systems) operate with the aid of transmission coil systems for emitting radiofrequency pulses to excite nuclear resonance and/or to receive induced magnetic resonance signals. An MR system may have a permanent magnet or a superconducting coil for producing a main magnetic field that is as homogeneous as possible in an examination area, at least one large whole-body coil arrangement permanently installed in the MR system. In order to read out electromagnetic signals and frequencies from which it is possible to produce images of a patient, gradient coils are used to produce magnetic field gradients in three axes that enable spatial coding relating to frequency information and phase information.
In order to excite the magnetic dipoles located in the examination object to emit MR signals, in addition to the whole-body coil arrangement, it is also possible to use local coil arrangements enabling the acquisition of images with a particularly high signal-to-noise ratio of selected areas of particular interest.
Both the whole-body coil arrangement and the local coil arrangements in most cases include a plurality of individual transmission coils that are intended to be driven as individually as possible. Such an MR system, which is intended to be able to drive the individual transmission coils of the whole-body coil arrangement as well as the local coil arrangement individually, correspondingly has a plurality of separate channels that are respectively connected to at least the whole-body coil arrangement and also the local coil arrangement, or even individually to the individual transmission coils present there.
MR systems thus equipped facilitate spatial influencing of the magnetic field that is used to excite the spinning system. If it is possible to drive the individual transmission coils completely independently at the MR frequency, new possibilities arise for improving image quality, for accelerating the measurement and for reducing the RF loading of the patient.
However, there is a problem of the outlay that increases with the number of the individual transmission coils, particularly with reference to the channels required in this case in the MR system in order to drive the transmission coils.